Drive reduction mechanism

ABSTRACT

An electric motor is secured to a side wall of a housing formed in part from a short length of stock metal tubing. The drive shaft of the motor is parallel to the axis of the tubing. A belt and pulley drive interconnects the motor shaft with one end of a worm shaft which extends axially through the tubular housing and meshes with a worm gear supported in the housing. The worm gear is secured to an output shaft which projects through a wall of the housing and extends perpendicular to the worm shaft. The worm shaft and the output shaft are supported by bearings contained within bearing housings which are welded to wall or closure portions of the tubular housing.

United States Patent Dahl [ 1 June 6,1972

[54] DRIVE REDUCTION MECHANISM [72] Inventor: Howard C. Dahl, 6420Nyanza Park Drive, Tacoma, Wash. 98499 [22] Filed: Jan. 11, 1971 21App]. No.: 105,540

[52] 11.5. C1 ..74/425, 254/170 [51] Int. Cl .Fl6h 1/18, B66d1/00 [58]Field of Search ..74/425; 254/170 [56] References Cited UNlTED STATESPATENTS 2,085,815 7/1937 McCollum ..254/170 2,578,151 12/1951 Ronfeldt....74/425 2,884,800 5/1959 Carrol ..74/425 Primary ExaminerLeonard H.Gerin Attomey-Graybeal, Cole & Barnard [57] ABSTRACT An electric motoris secured to a side wall of a housing formed in part from a shortlength of stock metal tubing. The drive shaft of the motor is parallelto the axis of the tubing. A belt and pulley drive interconnects themotor shaft with one end of a worm shaft which extends axially throughthe tubular housing and meshes with a worm gear supported in thehousing.

The worm gear is secured to an output shaft which projects through awall of the housing and extends perpendicular to the worm shaft. Theworm shaft and the output shaft are supported by bearings containedwithin bearing housings which are welded to wall or closure portions ofthe tubular housing.

7 Claims, 4 Drawing Figures BACKGROUND OF THE INVENTION comprise ahousing of cast construction to which a drive 1 motor is secured by aspecial end mount, with the shafi of the motor projecting into thehousing. A reduction gearing train is supported within'the housing andsuch gearing is interconnected between the motor shaft and an output orload shaft which projects outwardly from a wall portion of the housing.The end mounting of the motor requires a special mounting member, thecast housing requires that patterns be made, and the use of gearsexclusively in the reduction train requires the presence of severalgears, bearings for each gear, and a support wall or flange for eachgear designed into the housing. All of these features contribute tomaking the mechanism relatively expensive to manufacture. Also, the endmounting of the motor on the housing results in the motor projectingoutwardly from the housing an amount equal to its maximu dimension,i.e., its length.

Examples of known prior art reducer drive mechanisms of this type areshown by U.S. Pat. No. 2,67l,880, granted Mar. 9, 1954, to Ralph F.Symonds; by U.S. Pat. No. 2,759,703, granted Aug. 21, 1956, to Tracy S.Holmes; by U.S. Pat. No. 3,l40,856, granted July 14, 1964, to Edward F.Carpenter; and by U.S. Pat. No. 3,467,359, granted Sept. 16, 1969, toRoy L. Durand.

SUMMARY OF THE INVENTION The power drive mechanismv of the presentinvention is characterized by a reduction gearing housing fabricatedfrom a short length of metal tubing. A bottom wall is welded to one endof the tubular member and a cover is removably. secured to the oppositeend. A worm shaft extends axially through the housing and is supportedby bearings contained within bearing housings welded to the bottom walland the cover. A wonn section on the shaft meshes with a worm gearwithin the housing. The worm gear is pinned or otherwise secured to anintermediate portion of an output shaft. The output shaft is supportedfor rotation by means of bearings housed within bearing housings whichare welded to side wall portions of the tubular housing. A drive motor(e.g., electric) is mounted to a side wall of the housing with its shaftparallel to the worm shaft, whereby the motor adds its smaller (i.e.,its width) dimension to the housing, andmay be secured to the housing byuse of a conventional side located mounting plate. A belt and pulleydrive interconnects the motor shaft with one end of the worm shaft andprovides the first stage reduction, with the worm shaft providing asecond stage reduction.

According to the invention the housing may be bolted to one end of amounting base which may in part be fabricated from a length of standardstructural channel. A bearing carrying standard is bolted to theopposite end of such base to receive and support the opposite end of theoutput shaft. A winch drum or the like may be keyed or otherwise securedto the output shaft, to be driven thereby.

BRIEF DESCRIPTION OF THE DRAWING FIG. I is a side elevational view of awinch assembly constituting a preferred embodiment of the invention;

FIG. 2 is a sectional view, with some parts fragmented and some parts intop plan, taken substantially along line 2-2 of FIG. 1;

FIG. 3 is a vertical sectional view, with some parts shown in sideelevation, taken substantially along line 3-3 of FIG. 1; and

FIG. 4 is an exploded perspective view showing the principal componentsof the preferred embodiment, but omitting unimportant elements likebearings and fasteners, and also omitting the internal components of thegear reduction housmg.

DESCRIPTION OF THE PREFERRED EMBODIMENTS As best shown by FIGS. 1 and 4,the illustrated embodiment of the invention is a winch unit. Itcomprises a base member 10, an electric drive motor 12, a gear reductionhousing 14, a belt and pulley drive 16, a winch drum l8 and a supportstandard 20. I

The base member 10 comprises an upper mounting panel 22, short sidewalls 24, 26, and bolting plates 28, 30 welded to the lower edges of thewalls 24, 26 and extending laterally outwardly therefrom, substantiallyparallel to the mounting panel 22.

Preferably, the gear reduction housing 14 is fabricated from a shortlength of stock rectangular tubing cut from a long piece of tubing ofappropriate dimensions. As a result, its four side walls are ofone-piece construction. A bottom wall 32 is slightly inset into thebottom portion of tubular member 14, as shown by FIG. 3, and is weldedin place..Bolt receiving strips of metal 34 are welded to the inside ofmember 14 immediately adjacent the upper end thereof. A top plate 36 isremovably secured to the member 14 by a plurality of machine bolts 38which extend through sized openings in plate 36 and screw into tappedopenings formed in the strips 34.

The housing 14 is secured to one end of base member 10, such as by meansof nut and bolt assemblies) (FIG. 3) connecting bottom wall 32 to panel22. The drive motor 12 is secured to the outer side wall 42 of housing14, such as by means of nut and bolt assemblies 44 (FIG. 2). The boltsare shown to extend through slot apertures 46 provided in a mountingbase 48 on the motor 12, and through openings 50 in the side wall 42.

The drive shaft 52 of motor 12 is oriented to be in parallelsim with theaxis of housing 14. A relatively small diameter drive pulley 54 issecured to the motor drive shaft 52. Pulley 54 is connectedv to a secondlarger diameter pulley 56 by means of a V-belt 58. Pulley 58 is securedto the lower end portion of a worm shaft 60. Worm shaft 60 is verticallyoriented within end housing 14 and includes a drive worm 62 intennediateits ends. Worm 62 meshes with a worm gear 64.

According to the invention an upper bearing housing 66 of tubular formis welded to the top plate 36 and alower bearing housing 68, also oftubular form, is welded to the bottom plate 32. The bearing housings 66,68 are coaxially arranged and each houses appropriate bearings forhandling both radial loads and end thrust. Similarly, tubular bearinghousings 70, 72 (FIG. 2) are welded to opposed inside wall portions ofhousing 14 and receive suitable bearings for joumaling an output shaft76. The driven end of output shaft 76 projects through an opening madein wall 78, through bearing housing member 72 (and the bearing therein)welded to such wall 78 about such opening, then through the hub 80 ofworm gear 64, and into bearing housing 70 (and the bearing therein). Hub80 is pinned or otherwise secured to the output shaft 76.

The opposite end of output shaft 76 may be received within a suitablebearing contained within another bearing housing 82 which is welded orotherwise secured to the upstanding support standard 20. Standard 20 maybe fabricated from several pieces of plate material welded together. Itis shown to comprise a lower base plate 84 which is secured, such as bybolts 86( FIG. 1), to the end of top panel 22 opposite the housing 14.The winch drum 18 is pinned or otherwise secured to the output shaft 76.v

In this embodiment, a first gear reduction is obtained by the belt andpulley drive (e.g., in the order of 3.5:1 and a second in a quite simplemanner and by use of a small number of rela- 54, 56 and precisionorientation of the motor and worm shafts 52, 60, and this simplifiesconstruction.

In the illustrated embodiment the belt and pulley drive 16 is located atthe lower end of the motor, and the base member 10 is cut away at 88 toprovide clearance for the pulley 56. However, it is to be understoodthat in other embodiments the motor 12 could be turned end for end andthe belt and pulley drive 16 be relocated at the upper end of thehousing 14.

The upper end portion 90 of the worm shaft 60 is allowed to projectupwardly above the top plate 36. A hand crank or the like may beattached to this upper end portion 90 to provide a manual drive usablein case of motor failure, etc. Also, a brake may be attached to endportion 90 or end portion 90 may be used to drive an accessory. c

It is to be understood that something other than the winch drum 18 maybe secured to the output shaft 76 to be driven thereby. Also,.in someinstallations a relatively narrow winch drum 18 can be used and besupported solely by the bearings within bearing housing 70, 72, with thesupport standard 84 and the bearing carried thereby being eliminated.

Since the four sides and the top of gear housing 14 are planar, it isconvenient and easily possible to mount control units or other items onsuch side walls and top plate.

It is to be understood that these and other modifications can be madewithout departing from the spirit of the invention and the scope of theinvention is not to be limited to the illustrated embodiment and theforegoing description, but by the appended claims.

What is claimed is:

l. Reduction drive mechanism comprising:

wall means forming a housing;

a worm shaft in said housing having a worm section intermediate itslength;

a motor secured to an outside portion of said housing, and

' including a drive shaft in substantial parallelism with the wormshaft;

belt and pulley means dri'vingly connecting the drive shaft of the motorto an end portion of the worm shafi; output shaft means projectinglaterally through said housing generally perpendicularly to the wormshaft; and

a worm gear secured to said output shaft within said housing, said wormgear meshing with the worm section of the worm shaft.

2. Reduction drive mechanism according to claim I, wherein said housingis fabricated from a length of tubing and its wall means includes sidewall means of one-piece integral construction, and wherein an opening isprovided through a portion of the said side wall means for receiving theoutput shah means and a bearing-containing bearing housing is secured tosaid side wall means around said opening, and a portion of the outputshaft means extenck through the bearing housing.

3. Reduction drive mechanism according to claim 2, further comprisingclosure means for the opposite ends of said housing, each said closuremeans carrying a bearing housing and bearing means within said housingfor receiving an end portion of the worm shaft.

4. Reduction drive mechanism according to claim 2, wherein said lengthof tubing has rectangular proportions and the side wall means comprisesfour perpendicularly related side walls, said motor includes a sidelocated mounting plate, and said mounting plate is secured to one of thehousing side walls.

5. Reduction drive mechanism comprising: a short length of tubingforming one-piece slde wall means for a housing;

a worm shaft in said housing, extending axially thereof, and

including a worm section intermediate its length;

a motor including a drive shaft;

means drivingly connecting the drive shaft of the motor to an endportion of the worm shaft; 7

output shaft means projecting laterally through said housing generallyperpendicularly to the worm shaft;

a worm gear secured to said output shaft within said housing, said wormgear meshing with 'the worm section of the worm shaft;

bearing housings secured to opposed side wall portions of said housingsand including bearing means for receiving and joumaling the output shaftmeans for rotation; and

end closures for said housing, including opposed bearing housingsincluding bearing means for receiving and journaling the end portions ofsaid worm shaft.

6. Reduction drive mechanism according to claim 5, wherein said meansdrivingly connecting the drive shaft of the motor to an end portion ofthe worm shaft comprises a relatively small pulley on the drive shaft ofthe motor, a larger pulley secured to the end portion of the worm shaft,and a belt interconnecting the two pulleys, such belt and pulley driveproviding a first stage reduction and the worm and worm gear driveproviding a second stage reduction.

7. Reduction drive mechanism according to claim 5, further including anelongated base member, means securing one of the end closures of saidhousing, and hence the housing and its contents, to an end portion ofsaid base member, and means at the opposite end of said base member forreceiving and journaling the opposite end of the output shaft.

1. Reduction drive mechanism comprising: wall means forming a housing; aworm shaft in said housing having a worm section intermediate itslength; a motor secured to an outside portion of said housing, andincluding a drive shaft in substantial parallelism with the worm shaft;belt and pulley means drivingly connecting the drive shaft of the motorto an end portion of the worm shaft; output shaft means projectinglaterally through said housing generally perpendicularly to the wormshaft; and a worm gear secured to said output shaft within said housing,said worm gear meshing with the worm section of the worm shaft. 2.Reduction drive mechanism according to claim 1, wherein said housing isfabricated from a length of tubing And its wall means includes side wallmeans of one-piece integral construction, and wherein an opening isprovided through a portion of the said side wall means for receiving theoutput shaft means and a bearing-containing bearing housing is securedto said side wall means around said opening, and a portion of the outputshaft means extends through the bearing housing.
 3. Reduction drivemechanism according to claim 2, further comprising closure means for theopposite ends of said housing, each said closure means carrying abearing housing and bearing means within said housing for receiving anend portion of the worm shaft.
 4. Reduction drive mechanism according toclaim 2, wherein said length of tubing has rectangular proportions andthe side wall means comprises four perpendicularly related side walls,said motor includes a side located mounting plate, and said mountingplate is secured to one of the housing side walls.
 5. Reduction drivemechanism comprising: a short length of tubing forming one-piece sidewall means for a housing; a worm shaft in said housing, extendingaxially thereof, and including a worm section intermediate its length; amotor including a drive shaft; means drivingly connecting the driveshaft of the motor to an end portion of the worm shaft; output shaftmeans projecting laterally through said housing generallyperpendicularly to the worm shaft; a worm gear secured to said outputshaft within said housing, said worm gear meshing with the worm sectionof the worm shaft; bearing housings secured to opposed side wallportions of said housings and including bearing means for receiving andjournaling the output shaft means for rotation; and end closures forsaid housing, including opposed bearing housings including bearing meansfor receiving and journaling the end portions of said worm shaft. 6.Reduction drive mechanism according to claim 5, wherein said meansdrivingly connecting the drive shaft of the motor to an end portion ofthe worm shaft comprises a relatively small pulley on the drive shaft ofthe motor, a larger pulley secured to the end portion of the worm shaft,and a belt interconnecting the two pulleys, such belt and pulley driveproviding a first stage reduction and the worm and worm gear driveproviding a second stage reduction.
 7. Reduction drive mechanismaccording to claim 5, further including an elongated base member, meanssecuring one of the end closures of said housing, and hence the housingand its contents, to an end portion of said base member, and means atthe opposite end of said base member for receiving and journaling theopposite end of the output shaft.